There is an ongoing need in the fragrance industry to provide new chemicals to give perfumers and other persons the ability to create new fragrances for perfumes, colognes and personal care products. Those with skill in the art appreciate how differences in the chemical structure of the molecule can result in significant differences in the odor, notes and characteristics of a molecule. These variations and the ongoing need to discover and use the new chemicals in the development of new fragrances allow the perfumers to apply the new compounds in creating new fragrances.
Dihydropyran compounds are important raw materials for fragrances (See, U.S. Pat. No. 5,162,551). For example, phenyl-dihydropyrans such as 3,6-dihydro-4-methyl-2-phenyl-2H-pyran have long been used to prepare phenylpentanols such as 3-methyl-5-phenylpentanol, which is a valuable fragrance material (See, Swiss Patent No. 655932; Chinese Application Nos. 102731260 and 104876800). These dihydropyran compounds are themselves not considered as functional fragrances. Consistently, it has been well recognized by the perfume industry that while some dihydropyran compounds such as 6-(2-methyl-1-propenyl)-2,4,6-trimethyl-2H,5H-dihydropyran, 2,4-dimethyl-6-n-butyl-2,3dihydro-6H-pyran, 2,4-dimethyl-6-n-butyl-5,6-dihydro-2H-pyran, 2-methyl-4-methylene-n-butyltetrahydropyran and 3,6-dihydro-4,6-dimethyl-2-phenyl-2H-pyran were reported as functional fragrances, the usefulness in perfumery is no common property among all dihydropyrans (See, U.S. Pat. Nos. 3,309,276 and 3,681,263). Many dihydropyran compounds were prepared and investigated, yet no fragrance function could be established (See, U.S. Pat. Nos. 3,309,276, 3,681,263, 4,070,491 and 5,162,551).
Thus, skilled in the art appreciate that discovering a dihydropyran compound suitable for fragrance use is unpredictable. Further, small structural differences among dihydropyrans may result in compounds with distinctive fragrance properties, which are highly valuable. They allow perfumers to create perfumes with unique and distinguished characters.